JP2018517002A - Removable contact adhesive tape - Google Patents

Abstract

The present invention is a contact adhesive tape which includes an adhesive layer or more and can be re-peeled substantially without any residue and breakage by stretching and stretching on the application surface. The contact layer is made of a pressure-sensitive adhesive foamed by a microballoon and optionally includes one or more intermediate support layers. The disclosed contact adhesive tape is mainly composed of the adhesive material layer, optionally having one or more intermediate support layers, and the contact adhesive tape having one outer upper surface and one outer lower surface. Or more than the said adhesive material layer, it forms.

Description

  The present invention relates to a tear-resistant adhesive strip that is based on a vinyl block copolymer and can be used to provide a releasable bond by stretching in the direction of the application surface.

  Elastic and plastic highly extensible self-adhesive tapes that can be re-peeled without any residue and breakage by stretching and stretching on the pasting surface are, for example, US Pat. No. 4,024,312A (Patent Document 1), DE 3331016C2 (Patent Document 2), WO92. / 11332A1 (patent document 3), WO92 / 11333A1 (patent document 4), DE42222849C1 (patent document 5), WO95 / 06691A1 (patent document 6), DE19531696A1 (patent document 7), DE19626870A1 (patent document 8), DE19649727A1 (patent document) Document 9), DE19649728A1 (patent document 10), DE19649729A1 (patent document 11), DE197036464A1 (patent document 12), DE19720145A1 (patent document 13), DE19820858A1 (patent text) 14), WO99 / 37729A1 (Patent Document 15), and DE10003318A1 (known from Patent Document 16), hereinafter also referred to as strips, self adhesive tape.

  Such strippable self-adhesive tapes are often used in the form of pressure-sensitive adhesive film strips on one or both sides, and these adhesive film strips have a pinch area that is not pressure-sensitive adhesive. Preferably, the stripping process is initiated from this pick area. The special application of the corresponding self-adhesive tape is, among others, DE 4233882 C1 (patent document 17), DE 19511288C1 (patent document 18), US 5,507,464 B1 (patent document 19), US 5,672,402 B1 (patent document 20), and It is found in WO94 / 2157A1 (Patent Document 21). Special embodiments include DE 4428587C1 (Patent Document 22), DE 4431914C1 (Patent Document 23), WO 97 / 07172A1 (Patent Document 24), DE 19627400A1 (Patent Document 25), WO 98 / 03601A1 (Patent Document 26), and DE 19649636A1 (Patent Document 26). 27), DE 19720526A1 (Patent Literature 28), DE 19723177A1 (Patent Literature 29), DE 19723198A1 (Patent Literature 30), DE 19726375A1 (Patent Literature 31), DE 19756084C1 (Patent Literature 32), DE 19756816A1 (Patent Literature 33), DE 19842864A1 (Patent Literature 34). ), DE19842865A1 (Patent Document 35), WO99 / 31193A1 (Patent Document 36), WO99 / 377. 9A1 (Patent Document 15), WO99 / 63018A1 (Patent Document 37), WO00 / 12644A1 (Patent Document 38), and are also described in DE19938693A1 (Patent Document 39).

  The preferred fields of use of the strippable adhesive film strips described above include releasable fixation without residue and breakage of light to medium-weight objects, especially in residential, work and office areas. It is out. For use in the residential and office areas, products with a considerable thickness of over 400 μm are generally used.

  In the consumer electronics industry, for example, for the manufacture of mobile phones, digital cameras, or laptops, there is an increasing desire to be able to separate individual components when processing waste after use. It has become. In this case, some parts can be reused or recycled. Or at least the waste separation process becomes possible. Therefore, there is a great interest in this industry for releasable adhesive bonds. Here, inter alia, adhesive tapes that have high sticking performance and can be easily removed if desired are a significant alternative to adhesive strips that must first be pretreated for peeling, for example by heating.

  In the field of consumer electronics, the terminal strip should be as thin as possible, and therefore all individual components should not take up too much space, so as thin an adhesive strip as possible is preferred.

  When using very thin strippable adhesive strips produced without a support, tears are likely to occur (see DE 3331016C2). If the adhesive strip is torn, the remaining adhesive strip will bounce back into the adhesive joint, thus eliminating the knob and, of course, generally cannot be further peeled off.

  WO 92/11333 A1 describes a strippable adhesive tape that uses as a support a highly stretchable film with a restoring force <50% after stretching.

  WO 92/11332 A1 (Patent Document 3) describes an adhesive film strip that can be re-peeled by pulling on a sticking surface, which can use a highly stretchable and substantially non-restorable film as a support. Only UV-crosslinked acrylate copolymers are used as adhesives, and these adhesives cannot achieve high adhesive strength, such as adhesives based on vinyl aromatic block copolymers, for example. Less loss of adhesion during stretching than is the case with agents.

  Further publications such as WO 2010/141248 A1 describe a system with a polyisobutylene pressure sensitive adhesive with a similarly low adhesive strength.

  A strippable adhesive film strip with a foamed, non-pressure sensitive film support is disclosed in WO95 / 06691A1 (Patent Document 6), DE19649727A1 (Patent Document 9), DE19649728A1 (Patent Document 10), DE19649729A1 (Patent Document). 11), and DE19820858A1 (Patent Document 14). This foam material intermediate support does not allow strips of adhesive film with a thickness of less than 200 μm.

  Foam pressure sensitive adhesive systems have been known for a relatively long time and have been described in the prior art. Basically, polymer foam can be produced in two ways. One is due to the action of the foaming gas, whether added as a foaming gas or as a result of a chemical reaction, and the other is by incorporating hollow globules into the material matrix. Foams produced in the latter manner are referred to as syntactic foams.

  Adhesives foamed by micro hollow spheres are characterized by a defined cell structure with foam cells of uniform size distribution. The micro hollow spheres provide closed cell foams without holes, which are characterized by a better sealing action against dust and liquid media, compared to open cell configurations. In addition, chemically or physically foamed materials are relatively vulnerable to irreversible collapse under pressure and temperature, and often exhibit relatively low cohesive strength.

  Particularly advantageous properties can be achieved when inflatable microspheres (also called “microballoons”) are used as microspheres for foaming. Due to the flexible and thermoplastic polymer shell of inflatable microspheres, such foams have a higher conformability than those filled with inflatable and non-polymeric microhollow spheres (eg glass hollow spheres). . Such foams are better suited to compensate for manufacturing tolerances, as specified, for example, in the case of injection molded parts, and based on their foam properties, thermal stresses can also be better offset.

  Furthermore, the choice of polymer shell thermoplastic can further influence the mechanical properties of the foam. Thus, for example, foams with higher cohesive strength than the polymer matrix can be produced even if the foam has a density smaller than the matrix. Thus, for self-adhesive foams, typical foam properties such as the ability to conform to rough substrates can be combined with high cohesive strength.

  EP0257984A1 (Patent Document 41) discloses an adhesive tape having a foamed adhesive coating on at least one side. In this adhesive coating, polymer globules are contained, and the polymer globules themselves contain a liquid composed of hydrocarbons and expand when the temperature rises. The self-adhesive backbone polymer can consist of rubber or polyacrylate. Here, the microballoons are added before or after the polymerization. A self-adhesive containing microballoons is processed from a solvent and formed into an adhesive tape. In this case, the foaming step is necessarily performed after coating. A fine rough surface is thus obtained. On this basis, characteristics such as relocation properties in particular result. The effect of relatively good repositioning due to the microrough surface of the self-adhesive foamed by the microballoons is also described in further publications such as DE 3537433 A1 (patent document 42) or WO 95 / 31225A1 (patent document 43). .

  The fine rough surface is used to form a paste free of bubbles. This use also discloses EP0693097A1 (Patent Document 44) and WO98 / 18878A1 (Patent Document 45). Self-adhesive foamed by microballoons is also known from publications US Pat. No. 4,885,170A (patent document 46) and EP1102809B (patent document 47), but here the microballoons are adhesive tapes for permanent application which are not removable. It is used as a filler for

Devices in the consumer electronics industry are electronic, optical, and precision mechanical engineering equipment, and in the sense of this application, among other things, international goods and services for mark registration Classification (Nice Classification); Tenth Edition (NCL (10-2013)); Class 9 equipment (limited to electronic, optical, or precision mechanical engineering equipment); A timepiece and time measuring device based on Class 14 (NCL (10-2013)),
In particular:
・ Scientific instruments, ship navigation, surveying, photography, cinematography, optics, weighing, measurement, signal, inspection, lifesaving, and educational instruments and instruments Transformers, storage, adjustment, and control equipment and instruments ・ Equipment for image recording, processing, transfer, and playback, such as television and the like, and sound recording and processing, Transfer and playback equipment, eg radio and the like, computers, computing and data processing equipment, mathematical equipment and instruments, computer accessories, office equipment (eg printers, fax machines, copiers, typewriters) ), Data storage equipment, remote communication and multi-function equipment with remote communication functions, such as telephones, answering machines, chemical and physical measuring equipment, control equipment and instruments, eg Battery chargers, multimeters, lamps, speedometers, navigational instruments and instruments, optical instruments and instruments, medical instruments and instruments, and medical instruments and instruments for sportsmen, watches and chronometers・ Solar cell modules, such as electrochemical dye solar cells, organic solar cells, thin film batteries, and fire extinguishing equipment

  Technological developments are becoming increasingly smaller and lighter, and therefore are becoming devices that can be carried by the owner at any time and are usually always carried. This is usually brought about by the realization of the light weight and / or appropriate size of such equipment. Such a device is also referred to as a mobile device or a portable device within the scope of this specification. With this development trend, precision mechanical engineering and optical instruments are increasingly equipped with electronic components, which increases the possibility of minimization. Based on the carrying of mobile devices, these devices are already in constant motion, for example by hitting the edges, dropping, contacting other hard objects in the bag, but by carrying themselves. In particular, it is increasingly exposed to mechanical loads. However, mobile devices are more exposed to moisture, temperature effects, and similar loads than “fixed” devices that are usually installed indoors and do not move at all.

  Correspondingly, it is particularly preferred that the present invention relates to mobile devices. This is because the adhesive used according to the invention has a special utility here based on the unexpectedly superior properties of the adhesive (very high impact resistance). Several portable devices are listed below, but are not intended to unnecessarily limit the subject of the present invention by the representatives specifically listed in this list.

・ Cameras, digital cameras, photography accessories (eg exposure meter, flash device, aperture, camera housing case, objective lens, etc.), film cameras, video cameras, minicomputers (mobile computers, pocket computers, calculators), Laptops, notebook computers, netbooks, ultrabooks, tablet computers, handheld terminals, electronic calendars and system notebooks (so-called “Electronic Organizer” or “Personal Digital Assistant”, PDA, Palmtop), modem computers Accessories for electronic devices and operation units for electronic devices such as mice, pen tablets, graphic tablets, microphones, speakers, game consoles, Mupaddo, remote control, remote control device, the touch pad ( "Touchpad")
-Monitors, displays, screens, touch-sensitive screens (sensor screens, "touch screen devices"), projectors-Reading devices for electronic books ("E-Books")-Small televisions, pocket TVs, film playback devices, video playback Equipment / Radio (also small and pocket radio), Walkman, Discman, CD, DVD, Blu-ray, Cassette, USB, MP3 music playback equipment, headphone cordless phone, mobile phone, smartphone, wireless phone, hands-free phone , Calling equipment (pager, peeper)
・ Portable defibrillators, blood glucose level measuring devices, blood pressure measuring devices, pedometers, heart rate monitors / flashlights, laser pointers, portable detectors, optical magnification devices, telephoto devices, night vision devices / GPS devices, navigation devices , Satellite communication portable interface device / data storage device (USB stick, external hard disk, memory card)
・ Watches, digital watches, pocket watches, chain watches, stopwatches

  These devices require, among other things, adhesive tapes that have high retention performance and can be easily removed as desired.

  More importantly, even if an electronic device such as a mobile phone falls and collides downward, there is no problem in the holding performance of the adhesive tape. That is, the adhesive strip must have a very high impact resistance.

US4,024,312A DE3331016C2 WO92 / 11332A1 WO92 / 11333A1 DE42222849C1 WO95 / 06691A1 DE19531696A1 DE19626870A1 DE19649727A1 DE19649728A1 DE19649729A1 DE197036464A1 DE19720145A1 DE19820858A1 WO99 / 37729A1 DE10003318A1 DE4233872C1 DE19511288C1 US 5,507,464B1 US 5,672,402 B1 WO94 / 2157A1 DE4428587C1 DE44331914C1 WO97 / 07172A1 DE19627400A1 WO98 / 03601A1 DE19649636A1 DE19720526A1 DE19723177A1 DE19723198A1 DE197726375A1 DE 197556084C1 DE197556816A1 DE19842864A1 DE19842865A1 WO99 / 31193A1 WO99 / 63018A1 WO00 / 12644A1 DE199393693A1 WO2010 / 141248A1 EP0257984A1 DE3537433A1 WO95 / 31225A1 EP0693097A1 WO98 / 18878A1 US 4,885,170A EP1102809B WO2011 / 124782A1 DE102012223670A1 WO2009 / 114683A1 WO2010 / 077541A1 WO2010 / 078396A1 EP088941B1 EP1308492B1

J. et al. Brandrup, E.I. H. Immergut, E .; A. Grulk (Publisher), Polymer Handbook, 4th Edition 1999, Wiley, New York

  The problem of the present invention is that it can be re-peeled without any residue and breakage, especially by stretching in the direction of the application surface, and has particularly high impact resistance in the x, y and z planes and at the same time reduced adhesion Find the strips.

  This problem is solved according to the invention by a pressure-sensitive adhesive strip of the concept as described in claim 1. In this case, the subject matter of the dependent claims is an advantageous variant of the pressure-sensitive adhesive strip.

  Accordingly, the present invention is a pressure-sensitive adhesive strip comprising one or more adhesive layers, which can be re-peeled substantially free of residue and breakage by stretch stretching on the application surface, all of which The adhesive layer consists of a pressure sensitive adhesive foamed by a microballoon and optionally includes one or more intermediate support layers.

  The pressure-sensitive adhesive strip is mainly composed of the adhesive layer, optionally having one or more intermediate support layers, and the pressure-sensitive adhesive strip has one outer upper surface and one outer lower surface. Formed from one or more of the adhesive layers.

  The pressure-sensitive adhesive strip has an outer upper surface and an outer lower surface, and both the outer upper surface and the outer lower surface have additional layers, in particular other adhesive layers, which constitute the pressure-sensitive adhesive strip. Not included. Prior to use, the pressure-sensitive adhesive strip may be lined on one or both sides.

  It is essential in the present invention that the outer surface of the pressure-sensitive adhesive strip is easily adhered and formed by the foamed pressure-sensitive adhesive of the present invention. This is because the advantages of the present invention such as particularly high impact resistance in the x, y and z planes can be realized.

  According to a preferred embodiment, the pressure sensitive adhesive strip comprises an intermediate support located in the adhesive layer or between the two adhesive layers. The intermediate support is preferably formed of a film.

  According to another preferred embodiment, said pressure sensitive adhesive strip consists of a single adhesive layer.

  More preferably, the pressure-sensitive adhesive strip consists of the adhesive layer with a single intermediate support layer, in particular consisting of a polymer film.

  In order for the strippable adhesive film strips known in this connection to be peeled off easily and without residue, the adhesive film strips must have specific adhesive technical properties. That is, during stretching, the adhesive properties of the adhesive film strip must be clearly reduced. The lower the adhesion performance in the stretched state, the less the substrate is damaged during peeling.

  This property can be recognized particularly clearly with adhesives based on vinyl aromatic block copolymers, which in the case of these adhesives reduce the adhesion to below 10% in the vicinity of the yield point.

  In order for a strippable adhesive tape to be peeled off easily and without residue, the adhesive tape must have some specific mechanical properties in addition to the adhesive technical properties described above.

  It is particularly advantageous if the ratio of tear force to strip force is greater than 2, preferably greater than 3.

  This strip force is the force that must be expended for re-peeling the adhesive strip from the adhesive joint by parallel pulling in the direction of the application surface. The strip force is composed of a force necessary for peeling the adhesive tape from the sticking base as described above and a force that must be spent for deforming the adhesive tape. The force required for deformation of the adhesive tape depends on the thickness of the adhesive film strip.

  On the other hand, the force required for peeling does not depend on the thickness of the adhesive strip within the thickness range (20 to 2000 μm) considered for the adhesive film strip.

  The adhesive layer is preferably composed of a pressure sensitive adhesive, said pressure sensitive adhesive being composed on the basis of a vinyl aromatic block copolymer and an adhesive resin, in this regard at least (relative to the total resin proportion) A resin having a weight of 75% by weight, a DACP (diacetone alcohol cloud point) of more than −20 ° C., preferably more than 0 ° C., and a softening temperature (ring-and-ball type) of 70 ° C. or more, preferably 100 ° C. or more is selected.

As the vinyl aromatic block copolymer, a block copolymer having a structure of AB, ABAA, (AB) _n , (AB) _n X, or (ABAA) _n X At least one synthetic rubber in the form of
Where
Block A represents, independently of each other, a polymer formed by the polymerization of at least one vinyl aromatic;
Block B represents, independently of one another, a polymer formed by the polymerization of conjugated dienes and / or isobutylene having 4 to 18 C atoms or a partially or fully hydrogenated derivative of such a polymer. And
-X represents the residue of the coupling reagent or initiator, and-n represents the integer ≥2.

  In particular, all the synthetic rubbers of the pressure-sensitive adhesive according to the invention are block copolymers having a structure as described above. Accordingly, the pressure sensitive adhesive according to the present invention may also contain a mixture of various block copolymers having the structure as described above.

That is, suitable block copolymers (vinyl aromatic block copolymers) include one or more rubbery blocks B (soft blocks) and one or more glassy blocks A (hard blocks). Yes. Particularly preferred is that at least one synthetic rubber of the pressure-sensitive adhesive according to the invention has the structure AB, ABAA, (AB) ₃ X, or (AB) ₄ X. Wherein A, B, and X have the above meanings. Particularly preferred is a block in which all the synthetic rubbers of the pressure-sensitive adhesive according to the invention have the structure AB, AB-A, (AB) ₃ X, or (AB) ₄ X. A copolymer, where A, B, and X have the above meanings. In particular, the pressure sensitive adhesive synthetic rubber according to the invention is a mixture of block copolymers having the structure AB, ABAA, (AB) ₃ X, or (AB) ₄ X. And this mixture preferably contains at least a diblock copolymer AB and / or a triblock copolymer AB.

Further advantageous are mixtures of diblock and triblock copolymers and (AB) _n block copolymers or (AB) _n X block copolymers (n being 3 or more).

  As pressure sensitive adhesives, polymer blocks formed mainly by vinyl aromatics, preferably styrene (A blocks) and polymer blocks formed mainly by polymerization of 1,3-dienes such as butadiene and isoprene (B blocks) or It is preferred to use pressure sensitive adhesives based on block copolymers containing copolymers composed of these polymer blocks. This product may be partially or fully hydrogenated in the diene block. Vinyl aromatic and isobutylene block copolymers are also available in accordance with the present invention.

  The block copolymer of the pressure sensitive adhesive preferably has a polystyrene block.

  The block copolymers resulting from the A block and the B block can contain the same or different B blocks. The block copolymer can have a linear ABA structure. Radial form block copolymers and star and linear multi-block copolymers can also be used. As a further component, an AB biblock copolymer can be present. All of the above polymers can be utilized alone or mixed with one another.

Instead of the preferred polystyrene blocks, as vinyl aromatic, 75 ° C. aromatic other having a glass transition temperature of greater-containing homo- and copolymers (preferably C ₈ -C ₁₂ aromatic) polymer blocks based on, for example, α- A methylstyrene-containing aromatic block can also be utilized. It may further contain the same or different A blocks.

  The vinyl aromatic for forming block A preferably comprises styrene, α-methylstyrene, and / or other styrene derivatives. Block A can therefore exist as a homo or copolymer. It is particularly preferred that block A is polystyrene.

  Preferred conjugated dienes as monomers for the soft block B are selected from the group consisting of butadiene, isoprene, ethyl butadiene, phenyl butadiene, piperylene, pentadiene, hexadiene, ethyl hexadiene, and dimethyl butadiene, and any mixtures of these monomers, among others. The Block B can also be present as a homopolymer or as a copolymer.

  Particularly preferred is that the conjugated diene as monomer for the soft block B is selected from butadiene and isoprene. For example, the soft block B is a partially or fully hydrogenated derivative of one of polyisoprene, polybutadiene, or both polymers, such as polybutylene butadiene, in particular, or from a mixture of butadiene and isoprene. A polymer consisting of It is particularly preferred that block B is polybutadiene.

  The A block is also referred to as a “hard block” in the context of the present invention. Correspondingly, the B block is also referred to as “soft block” or “elastomer block”. This is in accordance with the invention of the block, depending on their glass transition temperature (at least 25 ° C., especially at least 50 ° C. for the A block and at most 25 ° C., especially at most −25 ° C. for the B block). Reflects the selection.

  In a preferred form, the total proportion of vinyl aromatic block copolymer, especially styrene block copolymer, relative to the total pressure sensitive adhesive is at least 20 wt%, preferably at least 30 wt%, more preferably at least 35 wt%.

  If the proportion of vinyl aromatic block copolymer is too low, the cohesiveness of the pressure sensitive adhesive will be relatively low and thus the tear strength required for stripping will be too low.

  The maximum proportion of vinyl aromatic block copolymers, in particular styrene block copolymers, in total with respect to the total pressure sensitive adhesive is at most 75% by weight, preferably at most 65% by weight, particularly preferably at most 55% by weight.

  Even if the proportion of the vinyl aromatic block copolymer is too high, the pressure-sensitive adhesive is almost not pressure-sensitive adhesive.

  Correspondingly, the proportion of vinyl aromatic block copolymer, in particular styrene block copolymer, relative to the total pressure sensitive adhesive is at least 20% by weight, preferably at least 30% by weight, more preferably at least 35% by weight. At the same time at most 75% by weight, preferably at most 65% by weight, particularly preferably at most 55% by weight.

  The pressure-sensitive adhesive according to the invention is based in particular on styrene block copolymers. The pressure sensitive adhesion of the polymer mixture is achieved by adding an adhesive resin that is miscible with the elastomer phase.

  The pressure sensitive adhesive contains at least one adhesive resin as well as at least one vinyl aromatic block copolymer to increase adhesion as desired. This adhesive resin is desirably compatible with the elastomeric block of the block copolymer.

“Adhesive resin” means that, according to the general understanding of those skilled in the art, the self-adhesiveness (tack, self-adhesion) of pressure-sensitive adhesives is higher than that of the same pressure-sensitive adhesives, although it does not contain adhesive resins. It is an oligomeric or polymeric resin to be made.

  Correspondingly, at least 75% by weight (relative to the total resin proportion), DACP (diacetone alcohol cloud point) is above -20 ° C, preferably above 0 ° C and softening temperature (ring-and-ball) is 70 ° C. As described above, a resin having a temperature of 100 ° C. or higher is preferably selected.

  Particularly preferred is that the adhesive resin is at least 75% by weight (relative to the total resin proportion) and is a hydrocarbon resin or a terpene resin or mixtures thereof.

As adhesion promoters for pressure sensitive adhesives, especially for non-polar hydrocarbon resins, for example, hydrogenated and non-hydrogenated polymers of dicyclopentadiene, C ₅ , C ₅ / C ₉ , Or non-hydrogenated, partially, selectively or fully hydrogenated hydrocarbon resins based on C ₉ monomer streams, α-pinene and / or β-pinene and / or δ-limonene It has been found advantageous to be able to use polyterpene resins based on. The above adhesive resins can be used alone or in a mixture. In this connection, a solid resin or a liquid resin can be used at room temperature. Optionally, it is preferred that hydrogenated or non-hydrogenated adhesive resins that also contain oxygen can be used up to a ratio of up to 25% of the total resin adhesive in the adhesive.

  The proportion of resin that is liquid at room temperature, according to a preferred embodiment, is up to 15% by weight, preferably up to 10% by weight, based on the total pressure-sensitive adhesive.

  The pressure-sensitive adhesive according to the present invention preferably contains at least one adhesive resin in an amount of 20 to 60% by weight based on the total weight of the pressure-sensitive adhesive. Particularly preferred is that the adhesive resin is contained in an amount of 30 to 50% by weight based on the total weight of the pressure-sensitive adhesive.

The following are typically available as further additives:
A plasticizer, such as a softening oil, or a low molecular liquid polymer, such as a low molecular weight polybutene, preferably in a proportion of 0.2 to 5% by weight, based on the total weight of the pressure sensitive adhesive. A primary antioxidant, such as a sterically hindered phenol Preferably in a proportion of 0.2 to 1% by weight relative to the total weight of the pressure sensitive adhesive; secondary antioxidants such as phosphites or thioethers, preferably 0.2 relative to the total weight of the pressure sensitive adhesive % To 1% by weight Process stabilizers such as C radical scavengers preferably 0.2 to 1% by weight relative to the total weight of the pressure sensitive adhesive Light stabilizers such as UV absorbers or steric hindrance Amines preferably in a proportion of 0.2 to 1% by weight relative to the total weight of the pressure sensitive adhesive. Processing aids preferably in a proportion of 0.2 to 1% by weight with respect to the total weight of the pressure sensitive adhesive. Reinforced resin preferred Or a proportion of 0.2 to 10% by weight relative to the total weight of the pressure sensitive adhesive, and in some cases preferably further polymers of elastomeric nature; correspondingly available elastomers include, among others Elastomers based on pure hydrocarbons, eg unsaturated polydienes such as natural or synthetically produced polyisoprene or polybutadiene, chemically substantially saturated elastomers, eg saturated ethylene-propylene copolymers, α- Based on olefin copolymers, polyisobutylene, butyl rubber, elastomers based on ethylene / propylene rubber, and chemically functionalized hydrocarbons such as halogen containing, acrylate containing, allyl containing or vinyl ether containing polyolefins Elastomer Preferably the proportion of 0.2 to 10% by weight relative to the total weight of the pressure sensitive adhesive

  The kind and amount of the mixed component can be selected as necessary.

  According to the present invention, the adhesive may not have some, preferably all, of each of the above admixtures.

  In one embodiment of the present invention, the pressure sensitive adhesive also contains additional additives, and illustratively, but without limitation, crystalline or amorphous oxides, hydroxides, carbonates , Nitrides, halides, carbides, or mixtures of aluminum, silicon, zirconium, titanium, tin, zinc, iron, or alkali (earth) metal oxide / hydroxide / halide compounds . This is substantially alumina, such as aluminum oxide, boehmite, bayerite, gibbsite, diaspore, and the like. Particularly suitable are layered silicates such as bentonite, montmorillonite, hydrotalcite, hectorite, kaolinite, boehmite, mica, vermiculite, or mixtures thereof. However, carbon black or further carbon modifications such as carbon nanotubes can also be used.

  The adhesive may be colored with a dye or pigment. The adhesive can be white, black, or color.

  As the softening agent, for example, (meth) acrylate oligomer, phthalate, cyclohexanedicarboxylic acid ester, water-soluble softening agent, soft resin, phosphate, or polyphosphate can be metered.

  In order to adjust the hot shear strength of the pressure sensitive adhesive, an additive of silica, preferably a precipitated silica surface-modified with dimethyldichlorosilane, can be used.

  According to one preferred embodiment of the invention, the adhesive consists only of vinyl aromatic block copolymer, adhesive resin, microballoon, and optionally the additives mentioned above.

More preferably, the adhesive comprises the following composition.
・ Vinyl aromatic block copolymer 20-75 wt%
・ Adhesive resin 24.6-60% by weight
・ Microballoon 0.2 ~ 10wt%
・ Additive 0.2-10% by weight

More preferably, the adhesive comprises the following composition.
・ Vinyl aromatic block copolymer 35-65 wt%
・ Adhesive resin 34.6-45 wt%
・ Microballoon 0.2 ~ 10wt%
・ Additive 0.2-10% by weight

More preferably, the adhesive comprises the following composition.
・ Vinyl aromatic block copolymer 30-75 wt%
・ Adhesive resin 24.8-60% by weight
・ Microballoon 0.2 ~ 10wt%

  The pressure sensitive adhesive according to the invention is foamed. Foaming is preferably obtained by introduction of a microballoon and subsequent expansion.

  “Microballoons” are micro-hollow spheres that are elastic and thus expandable in their basic state with a thermoplastic polymer shell. The sphere is filled with a low boiling liquid or liquefied gas. As shell material, polyacrylonitrile, PVDC, PVC or polyacrylate is used, among others. Suitable low-boiling liquids are, in particular, lower alkane hydrocarbons, such as isobutane or isopentane, which are trapped in the polymer shell as a liquefied gas under pressure.

  Due to the action on the microballoons, the outer polymer shell is softened, in particular by thermal action. At the same time, the liquid foam gas in the shell shifts to its gaseous state. At that time, the microballoon expands irreversibly and expands in three dimensions. The expansion ends when the internal pressure and the external pressure are balanced. Since the polymer shell is maintained, a closed cell foam is thus obtained.

  A number of microballoon types are commercially available, and microballoon types are distinguished by their size (unexpanded diameter 6-45 μm) and the starting temperature required for expansion (75-220 ° C.). An example of a commercially available microballoon is the Expando® DU type (DU = dry unexpanded) from Akzo Nobel.

  The unexpanded microballoon type can be used as an aqueous dispersion with a solid or microballoon ratio of about 40-45% by weight, and also with polymer-bonded microballoons having a microballoon concentration of, for example, about 65% by weight in ethylene vinyl acetate. It is also available as a balloon (masterbatch). Both microballoon dispersions and masterbatches are suitable for the production of foamed pressure-sensitive adhesives like the DU type.

  The foamed pressure-sensitive adhesive according to the invention can also be produced by so-called inflated microballoons. In this group, the expansion has already taken place before being incorporated into the polymer matrix. Pre-expanded microballoons are commercially available from Akzo Nobel, for example under the name Dualite® or with the type name Expandel xxx DE (Dry Expanded).

  Preferred according to the present invention is that at least 90% of all the hollow spaces formed by the microballoons have a maximum diameter of 10 to 200 μm, more preferably 15 to 200 μm. “Maximum diameter” refers to the maximum width of the microballoon in any spatial direction.

  The diameter is determined by a scanning electron microscope (REM) with a magnification of 500 times, based on the frozen fracture edge (Kryobruchkante). From each individual microballoon, the diameter is determined by image.

  When foamed by a microballoon, the microballoon can be supplied as a batch of formulation, as a paste, or as a powder with or without a blend. The microballoon can be further suspended in a solvent.

  According to a preferred embodiment of the invention, the proportion of microballoons in the adhesive is between more than 0% and 10% by weight, in particular 0.25% to 5%, respectively, relative to the total composition of the adhesive. %, Especially between 0.5 and 1.5% by weight.

  This data is for uninflated microballoons.

  The polymer agent according to the invention containing inflatable micro hollow spheres may additionally contain non-inflatable micro hollow spheres. All that matters is that almost all the cavities containing the gas are permanently closed by a tightly sealed membrane, so that the membrane consists of a polymer mixture that is elastic and can be stretched thermoplastically. It does not matter whether it consists of a glass that is elastic and not thermoplastic in the temperature spectrum, which can be plastic processing, for example.

  Suitable for pressure-sensitive adhesives according to the invention are furthermore polymer solid spheres, glass hollow spheres, glass solid spheres, ceramic hollow spheres, ceramic solid spheres and / or carbon solid spheres (“carbon microballoons”). ]), Selected independently from other additives.

The absolute density of the foamed pressure-sensitive adhesive is preferably 350 to 990 kg / m ³ , more preferably 450 to 970 kg / m ³ , especially 500 to 900 kg / m ³ .

  The relative density represents the ratio of the density of the foamed pressure-sensitive adhesive according to the invention to the density of the same formulation and unfoamed pressure-sensitive adhesive according to the invention. The relative density of the pressure sensitive adhesive according to the invention is preferably 0.35 to 0.99, more preferably 0.45 to 0.97, especially 0.50 to 0.90.

When the pressure-sensitive adhesive according to the invention has one (or two or more) intermediate supports, the absolute density of the foamed pressure-sensitive adhesive according to the invention is preferably between 220 and 990 kg / m ³ , more preferably Is between 300 and 900 kg / m ³ , especially between 500 and 850 kg / m ³ .

  The relative density in this case is preferably between 0.20 and 0.99, more preferably between 0.30 and 0.90, especially between 0.50 and 0.85.

The adhesive tape manufactured using the polymer foam according to the present invention can be formed as the following adhesive tape.
• Single-sided self-adhesive adhesive tape (so-called “transfer tape”) consisting of only one layer of foamed pressure-sensitive adhesive
A double-sided, double-sided self-adhesive tape, each layer consisting of the PSA of the present invention; an adhesive tape finished to self-adhesion on both sides with an intermediate support located in or between the two adhesive layers.

  A single-sided, self-adhesive tape, preferably consisting of only one layer of foamed pressure sensitive adhesive.

  A preferred embodiment of the pressure sensitive adhesive strip is a pressure sensitive adhesive strip having an intermediate support consisting of only a single layer of polymer film.

  The double-sided product can have a symmetric or asymmetric product structure.

  Included in the idea of the invention is a pressure sensitive adhesive strip, particularly a structure with an extensible intermediate support in the middle of a single pressure sensitive adhesive layer, where the extensibility of the intermediate support is: It must be sufficient to ensure peeling of the adhesive strips by stretching. As the intermediate support, for example, a very stretchable film can be used. Examples of extensible intermediate supports that can be advantageously used are WO2011 / 124782A1 (Patent Document 48), DE102012223670A1 (Patent Document 49), WO2009 / 114683A1 (Patent Document 50), WO2010 / 077541A1 (Patent Document 51), WO2010 / 078396A1. It is a transparent embodiment from US Pat.

  For the production of the intermediate support film, film-forming or extrudable polymers are used, which can additionally be uniaxially or biaxially oriented.

  In one preferred design, polyolefin is used. Preferred polyolefins are produced from ethylene, propylene, butylene and / or hexylene, each being able to polymerize pure monomers or copolymerizing a mixture of the listed monomers. Depending on the polymerization method and on the choice of monomers, the physical and mechanical properties of the polymer film, such as eg softening temperature and / or tear strength, can be controlled.

  Polyurethane can be used more advantageously as a starting material for the extensible intermediate support layer. Polyurethanes are chemically and / or physically crosslinked polycondensates typically formed from polyols and isocyanates. Depending on the type of individual components and the proportions used, extensible materials can be obtained which can be used advantageously in the meaning of the invention. For this purpose, raw materials available to the formulator are listed, for example, in EP088941B1 (Patent Document 53) and EP1308492B1 (Patent Document 54). The person skilled in the art knows further raw materials that can form the intermediate support layer according to the invention. In order to achieve extensibility, it is further advantageous to use a rubber-based material for the intermediate support layer. As a starting material for the extensible intermediate support layer, natural rubber is basically of the crepe type, RSS type, ADS type, TSR type or CV type as rubber or synthetic rubber or a mixture produced therefrom. From all available qualities such as, depending on the level of purity and viscosity required, one or more synthetic rubbers can be statistically copolymerized styrene-butadiene rubber (SBR), Group of butadiene rubber (BR), synthetic polyisoprene (IR), butyl rubber (IIR), halogenated butyl rubber (XIIR), acrylate rubber (ACM), ethylene vinyl acetate copolymer (EVA), and polyurethane, and / or mixtures thereof You can choose from.

  A block copolymer can be used particularly advantageously as a material for the extensible intermediate support layer. In this regard, the individual polymer blocks are covalently linked to each other. Block linkages can be in linear form but can also be in the form of stars or graft copolymers. An example of a block copolymer that can be used advantageously is a linear triblock copolymer, the softening temperature of the blocks at both ends being at least 40 ° C., preferably at least 70 ° C., and the softening temperature of the middle block is At most 0 ° C., preferably at most −30 ° C. Higher order block copolymers such as tetrablock copolymers may be used. Importantly, the block copolymer contains at least two polymer blocks of the same or different types, and the softening temperatures of these polymer blocks are at least 40 ° C., preferably at least 70 ° C., respectively. Are polymer chains that are separated from each other via at least one polymer block with a softening temperature of at most 0 ° C., preferably at most −30 ° C. Examples of polymer blocks are polyethers such as polyethylene glycol, polypropylene glycol, or polytetrahydrofuran, polydienes such as polybutadiene or polyisoprene, hydrogenated polydienes such as polyethylene butylene or polyethylene propylene, polyesters such as polyethylene terephthalate, polybutanediol azide. Part or polyhexanediol adipate, polycarbonate, polycaprolactone, polymer blocks of vinyl aromatic monomers, eg polystyrene or poly [α] methylstyrene, polyalkylvinylether, polyvinyl acetate, [α], [β] Polymer blocks of saturated esters, for example acrylates or methacrylates, among others. The corresponding softening temperature is known to those skilled in the art. Instead, those skilled in the art, for example, see the Polymer Handbook [J. Brandrup, E.I. H. Immergut, E .; A. The softening temperature is examined by Grulk (issuer), Polymer Handbook, 4th edition 1999, Wiley, New York (Non-Patent Document 1)]. The polymer block may be formed from a copolymer.

  With respect to the production of the intermediate support material, here too, additives that improve the film-forming properties, reduce the tendency to form crystalline segments and / or improve the mechanical properties accurately or even if necessary Additional ingredients can be added.

  More suitable are sheet-like foam materials (eg consisting of polyethylene and polyurethane).

  The intermediate support can be formed in multiple layers.

  The intermediate support can further have an overcoat layer, for example, can have a barrier layer that prevents entry of components from the adhesive into the intermediate support or vice versa. These overcoat layers may have barrier properties to prevent water and / or oxygen permeation and diffusion.

  In order to improve the fixing of the pressure sensitive adhesive to the intermediate support, the intermediate support can be pretreated by known measures such as corona, plasma, or flame. Primers can also be used. However, it is ideal to eliminate the pretreatment.

  The back surface of the intermediate support can be provided with an anti-adhesive physical treatment or coating.

  Finally, the pressure-sensitive adhesive strip can be lined on one or both sides with release paper coated anti-adhesive on both sides, ie a temporary support.

  The liner (release paper, release film) is not a component of the adhesive tape, but merely an aid for the production, storage, or further processing by die-cutting of the adhesive tape. In addition, the liner is not fixedly bonded to the adhesive material layer, unlike the adhesive tape support.

  The thickness of this intermediate support layer is in the range of 10-200 μm, preferably between 20-100 μm.

  In order to enable easy peeling without using too much force, it is desirable that the stress at an elongation of 50% is less than 20 N / cm, preferably less than 10 N / cm.

Particularly advantageous are adhesive film strips,
Consists of an intermediate support, preferably made of polyurethane, which support has a tear elongation of at least 100%, preferably 300%, and in some cases more than 50% restoring force;
The adhesive layer made of the adhesive according to the present invention based on the vinyl aromatic block copolymer and the adhesive resin is applied to both surfaces of the support, respectively, and the composition of the adhesive is the same. Further preferred.

  Manufacture and processing of pressure sensitive adhesives can be done from solution or from melt. Application of the pressure sensitive adhesive on the intermediate support layer can be effected by direct coating or by laminating, in particular hot laminating.

  Typical finishes for pressure sensitive adhesive strips according to the present invention are adhesive tape rolls and adhesive strips such as obtained, for example, in the form of die cuts.

  It is preferable that all the layers have a substantially rectangular parallelepiped shape. More preferably, all layers are bonded to one another over the entire surface.

  Optionally, a knob region that is not pressure-sensitive adhesive can be provided, and a peeling process can be performed from this knob region.

  The general expression “adhesive tape” in the sense of the present invention is a two-dimensionally spread film or film section, a tape having an extended length and a limited width, a tape section, a die cut, a label, and its Includes all planar formations, such as analogs.

  The thickness of the (single layer) adhesive film strip is preferably 20 μm to 2000 μm, more preferably 30 to 1000 μm, particularly preferably 50 to 600 μm, 100 μm, 150 μm or 300 μm.

  Preference is given to pressure-sensitive adhesive strips in which the thickness of the support is between 20 and 60 μm, preferably 50 μm, and the thickness of the same adhesive layer on the support is also between 20 and 60 μm, preferably 50 μm respectively. It is one embodiment of a piece.

  Two embodiments are particularly preferred in this regard: the first embodiment has a 25 μm adhesive on both sides of a 50 μm thick support and the second embodiment is a 30 μm thick support. On both sides, it has a 35 μm adhesive.

  A particularly advantageous embodiment of the invention will be described in more detail on the basis of the figures and examples described below, without intending to limit the invention unnecessarily thereby.

FIG. 3 shows a three-layer pressure sensitive adhesive strip according to the present invention. FIG. 6 shows a three layer pressure sensitive adhesive strip according to the present invention in an alternative embodiment. 1 shows a single pressure sensitive adhesive strip according to the invention. FIG. FIG. 6 shows a method using one mixing unit, in which case the microballoon is added immediately in the first mixing unit. FIG. 4 shows a method using two mixing units, in which case the microballoon is added in the first mixing unit. FIG. 6 shows a method using two mixing units, in which case the microballoons are finally added in the second mixing unit. 6 is a cross-sectional view from the side of a sample based on Example 5. FIG. 10 is a cross-sectional view from the side of a sample based on Example 8. FIG.

  FIG. 1 shows a pressure-sensitive adhesive strip according to the invention consisting of three layers 1, 2 and 3, which is substantially free from residue and breakage due to stretching at the application surface. It can be peeled again.

  The strip consists of an intermediate support 1, which is implemented in one layer.

  On both sides of the intermediate support are the outer adhesive layers 2, 3 according to the invention.

  The protruding end portion of the intermediate support layer 1 can be used as a knob portion, but does not necessarily exist.

  FIG. 2 shows a pressure sensitive adhesive strip according to the invention in one form. This pressure-sensitive adhesive strip consists of three layers 1, 2, 3 arranged to overlap completely equally.

  In particular, one end of the adhesive film strip is preferably coated with a silicone-treated film piece or paper piece 6 on both sides in order to produce a knob portion that is pulled to achieve stretching and stretching on the application surface. Finished so as not to be pressure-bonded.

  FIG. 3 shows a single pressure-sensitive adhesive strip 1 having a knob portion consisting of a silicone-treated film strip or paper strip 6 applied to both sides of the adhesive strip 1.

The invention further comprises one method (see FIG. 4) for producing an adhesive according to the invention containing inflated microballoons, in which case
The components for forming the adhesive, such as a polymer, resin or filler, and the unexpanded microballoon are mixed in the first mixing unit and heated to the expansion temperature under overpressure;
The microballoons expand as they exit the mixing unit,
-Mold the adhesive mixture into a single layer in a roll coater with the expanded microballoons,
• In some cases, the adhesive mixture, including the expanded microballoon, is applied on a sheet-like support material or release material.

The invention also includes one method (see FIG. 5) for producing an adhesive according to the invention containing inflated microballoons, in which case
A component for forming an adhesive, such as a polymer, resin, or filler, is mixed with the unexpanded microballoon in an overpressure in the first mixing unit and below the expansion temperature of the microballoon Adjust the temperature to the temperature,
Transferring the mixed, in particular homogeneous, adhesive from the first mixing unit to the second unit and heating to the expansion temperature under overpressure;
Inflates when the microballoon exits in or out of the second unit;
-Mold the adhesive mixture into a single layer in a roll coater with the expanded microballoons,
• In some cases, the adhesive mixture, including the expanded microballoon, is applied on a sheet-like support material or release material.

The invention also relates to one method (see FIG. 6) for producing an adhesive according to the invention containing inflated microballoons, in which case
Mixing the components for forming the adhesive, such as polymers, resins or fillers, in the first mixing unit;
Transferring the mixed, in particular homogeneous, adhesive from the first mixing unit to the second mixing unit and simultaneously feeding the second mixing unit with unexpanded microballoons;
Inflates when the microballoon exits in or out of the second mixing unit;
-Mold the adhesive mixture into a single layer in a roll coater with the expanded microballoons,
• In some cases, the adhesive mixture, including the expanded microballoon, is applied on a sheet-like support material or release material.

  According to a preferred embodiment of the present invention, the adhesive is molded in a roll coater and applied onto a support material.

  Adhesives foamed by microballoons generally do not need to be degassed before coating in order to obtain a uniform and consistent coating appearance. Air trapped in the adhesive during compounding is expelled by the expanding microballoon. Nevertheless, at high throughput, it is better to degas the adhesive before coating in order to obtain a uniform adhesive supply at the roll gap. The degassing is ideally performed immediately before the roll coater with a differential pressure of at least 200 mbar relative to the mixing temperature and ambient pressure.

The following cases are further advantageous.
The first mixing unit is a continuous unit, in particular a planetary roll extruder, a twin screw extruder, or a pin extruder,
The first mixing unit is a discontinuous unit, in particular a Z-blade kneader or a closed mixer,
The second mixing unit is a planetary roll extruder, a single or twin screw extruder, or a pin extruder, and / or a molding that molds the adhesive into a single support layer with an expanded microballoon. A unit is a gap formed by a calendar machine, a roll coater, or a roll and a stationary doctor blade.

  In the process according to the invention, all previously known and described adhesives, in particular the components of self-adhesive adhesives, can be processed without solvents.

  Hereinafter, the above-described method within the concept of the present invention will be specifically described with a particularly excellent configuration. However, there is no intention to unnecessarily limit the selected method.

  FIG. 4 shows a particularly advantageously constructed method for producing foamed pressure sensitive adhesive strips.

  The pressure sensitive adhesive is produced in a continuous mixing unit such as a planetary roll extruder (PWE).

  For this purpose, the reactant E forming the adhesive is fed into the planetary roll extruder PWE1. At the same time, the unexpanded microballoon MB is homogeneously mixed under pressure in the self-adhesive during the compounding process.

  Necessary for the temperature required for homogeneous production of the self-adhesive and the expansion of the microballoon so that when the microballoon exits PWE1, it will foam in the self-adhesive M due to the pressure drop at the nozzle outlet and break through the adhesive surface Adapt to each other.

  This foam adhesive M is calendered by a roll coater 3 as a molding unit and coated on a sheet-like support material such as release paper TP, and in some cases, further foaming occurs in the gap between the rolls. Can do. The roll coater 3 includes a doctor roll 31 and a coating roll 32. The release paper TP is guided to the coating roll 32 by the pickup roll 33, and thus the release paper TP takes over the adhesive K from the coating roll 32.

  At the same time, the inflated microballoon MB is pushed again into the polymer matrix of adhesive K, thus producing a smooth surface.

  In FIG. 5 a further particularly advantageously configured method for producing a foamed pressure sensitive adhesive strip is shown.

  The planetary roll extruder PWE1 has two mixing zones 11, 12 connected one after the other, in which the central spindle rotates. There are also six planetary spindles per heating zone. To the injection ring 13, additional reactants such as softeners or liquid resins are added.

  Suitable equipment is, for example, the Entex planetary roll extruder in Bochum.

  Subsequently, in a second mixing unit such as a single screw extruder, the microballoon is mixed homogeneously into the self-adhesive under overpressure, heated above the expansion temperature and foamed as it exits. . For this purpose, the adhesive K formed from the reactant E is fed here into the single screw extruder ESE2 and simultaneously filled with the microballoons MB. The single screw extruder ESE has a total of four heating zones over the treatment length 21.

  A suitable device is, for example, a single screw extruder from Kiener.

  The microballoon MB breaks through the adhesive surface during expansion caused by the pressure drop at the nozzle exit of ESE2.

  By the roll coater 3, this foam adhesive M can be calendered and coated on a sheet-like support material such as release paper TP, and in some cases, post foaming can be further caused in the roll gap. The roll coater 3 includes a doctor roll 31 and a coating roll 32. The release paper TP is guided to the coating roll 32 by the pickup roll 33, and thus the release paper TP takes over the adhesive K from the coating roll 32.

  At the same time, the inflated microballoon MB is pushed again into the polymer matrix of adhesive K, thus producing a smooth surface.

  FIG. 6 shows a further particularly advantageous structured method for producing foamed pressure-sensitive adhesive strips.

  The pressure sensitive adhesive is produced in a continuous mixing unit such as a planetary roll extruder (PWE).

  Here, the reactant E forming the adhesive is supplied into the planetary roll extruder PWE1. The planetary roll extruder PWE1 has two mixing zones 11, 12 connected one after the other, in which the central spindle rotates. There are also six planetary spindles per heating zone.

  To the injection ring 13, additional reactants such as softeners or liquid resins are added.

  Suitable equipment is, for example, the Entex planetary roll extruder in Bochum.

  Subsequently, in a second mixing unit such as a single screw extruder, the microballoon is mixed homogeneously into the self-adhesive under overpressure, heated above the expansion temperature and foamed as it exits. . For this purpose, the adhesive K formed from the reactant E is fed here into the single screw extruder ESE2 and simultaneously filled with the microballoons MB. The single screw extruder ESE has a total of four heating zones over the treatment length 21.

  A suitable device is, for example, a single screw extruder from Kiener.

  The microballoon MB breaks through the adhesive surface during expansion caused by the pressure drop at the nozzle exit of ESE2.

  By the roll coater 3, this foam adhesive M can be calendered and coated on a sheet-like support material such as release paper TP, and in some cases, post foaming can be further caused in the roll gap. The roll coater 3 includes a doctor roll 31 and a coating roll 32. The release paper TP is guided to the coating roll 32 by the pickup roll 33, and thus the release paper TP takes over the adhesive K from the coating roll 32.

  At the same time, the inflated microballoon MB is pushed again into the polymer matrix of adhesive K, thus producing a smooth surface.

As can be seen from FIG. 4, as the gap pressure in the roll gap decreases, the push-back of the microballoons becomes weaker, thus reducing the application area of the coated foamed self-adhesive. FIG. 4 shows the application area according to the coating method or the coating parameters. The required gap pressure is strongly dependent on the adhesive system used, the higher the viscosity, the higher the gap pressure, depending on the desired layer thickness and the selected coating speed. In practice, at particularly high coating speeds of more than 50 m / min, a pore pressure of more than 4 N / mm has proven to be suitable, with low adhesive application (weight per unit area less than 70 g / m ² ) and high In the case of a viscous adhesive (50,000 Pa · s at 0.1 rad and 110 ° C.), a pore pressure of more than 50 N / mm may be required.

  It has proven suitable to adapt the temperature of the roll to the expansion temperature of the microballoon. Ideally, the roll temperature of the initial roll should exceed the inflation temperature of the microballoons to allow post-foaming of the microballoons without destroying the microballoons. The temperature of the last roll is preferably below the expansion temperature, so that the microballoon shell can be cured and a smooth surface according to the present invention is formed.

  Many units are known for the continuous production and processing of solvent-free polymer systems. Screw machines such as single and twin screw extruders are often used with very various process lengths and equipment. However, a wide variety of structural types of kneaders operating continuously, for example combinations of kneaders and screw machines, or planetary roll extruders, are also used for this task.

  Planetary roll extruders have been known for a long time and are initially used for the processing of thermoplastics such as PVC, where the planetary roll extruder mainly follows, for example, a calender or rolling machine Used to feed the unit. Its use due to the advantages of planetary roll extruders with large surface renewal for material exchange and heat exchange that can quickly and effectively discharge the energy brought about by friction, short residence time and narrow residence time spectrum The field has recently expanded, especially to compounding processes that require a temperature-controlled flow system.

  Planetary roll extruders come in various embodiments and sizes depending on the manufacturer. Depending on the desired throughput, the barrel diameter is typically between 70 mm and 400 mm.

  The planetary roll extruder generally has a filling part and a compounding part.

  The filling part consists of a conveying screw, and all solid components are continuously dispensed onto this conveying screw. Thereafter, the conveying screw delivers the material to the compounding section. The area of the filling section with the screw is preferably cooled to avoid material sticking to the screw. However, there are also embodiments without a screw part, in which case the material is fed directly between the central spindle and the planetary spindle. However, this is not important for the effectiveness of the method according to the invention.

  The compounding part consists of a single driven central spindle and a plurality of planetary spindles, which orbit around the central spindle in one or more barrels with internal inclined teeth. The number of rotations of the central spindle and hence the orbiting speed of the planetary spindle is variable and is therefore an important parameter for controlling the compounding process.

  The material circulates between the central spindle and the planetary spindle or between the planetary spindle and the inclined teeth of the barrel part, so that the material is brought into a homogeneous compound under the influence of shear energy and external temperature regulation. Distribution is performed.

  The number of planetary spindles orbiting within each barrel is variable and can therefore be adapted to process requirements. The number of spindles affects the free volume in the planetary roll extruder, the residence time of the material in the process, and additionally determines the area for heat exchange and material exchange. The number of planetary spindles affects the compound result through the resulting shear energy. With a constant barrel diameter, better homogenization and dispersion performance or greater product throughput can be achieved as the number of spindles increases.

  The maximum number of planetary spindles that can be mounted between the central spindle and the barrel depends on the diameter of the barrel and the diameter of the planetary spindle used. When using a relatively large barrel diameter or a relatively small diameter of a planetary spindle as necessary to achieve a throughput rate on a production scale, this barrel may be equipped with a relatively large number of planetary spindles. it can. Typically, a maximum of 7 planetary spindles with a barrel diameter D = 70 mm are used, while for example 10 planetary spindles with a barrel diameter D = 200 mm and 24 planetary spindles with a barrel diameter D = 400 mm are used. can do.

  According to the invention, it has been proposed that the foamed adhesive coating be carried out by a multi-roll coater without a solvent. This can be a coater consisting of at least two rolls with at least one roll gap to five rolls with three roll gaps.

  A coating mechanism such as a calender (I, F, L type calender) is also conceivable, whereby the foamed adhesive is formed to the desired thickness as it passes through one or more roll gaps.

  In doing so, it has been found to be particularly advantageous to select the temperature control of the individual rolls so that foaming can possibly occur after controlled. In this manner, the delivering roll can be above the foaming temperature of the selected microballoon type, while the receiving roll is below the foaming temperature to prevent uncontrolled foaming. And in this case all the rolls can be individually adjusted to a temperature of 30-220 ° C.

  In order to improve the delivery behavior of the shaped adhesive layer from one roll to the other, a roll or doctor roll finished anti-adhesive can be used. In order to produce a sufficiently precise adhesive material film, the peripheral speed of the roll can be differentiated.

  A preferred four roll coater is formed by a dosing roll, a doctor roll that determines the layer thickness on the support material and is arranged parallel to the dosing roll, and a transfer roll under the dosing roll. The adhesive and the sheet-like material are guided together on the leion roll that forms the second roll gap together with the transfer roll.

  Depending on the type of sheet-like support material to be coated, the coating can be carried out in the same or reverse direction.

  The forming unit can also be formed by a gap formed between the roll and the stationary doctor blade. The stationary doctor blade can be a doctor knife or a stationary (semi) roll.

  In an alternative manufacturing method, all components of the adhesive are dissolved in a solvent mixture (benzine / toluene / acetone). The microballoon was suspended in benzine and mixed into the melted adhesive. As soon as the microballoons are homogeneously dispersed in the solution, the adhesive can be coated onto a conventional PET liner, for example by a doctor blade.

  In the first step, the coated adhesive is bare and dried at 100 ° C. for 15 minutes.

  After drying, the adhesive layer is covered with the second layer, a PET liner, and foamed for 5 minutes in a 150 ° C. oven. That is, it is sandwiched between two liners to produce a particularly smooth surface.

Roughness _{R a} of the generated surface in this way is less than 15 [mu] m, particularly preferably less than 10 [mu] m.

Surface roughness is the industry standard unit for surface finish quality, _Ra is the average height of the roughness, and in particular the average absolute distance from the centerline of the roughness profile in the evaluation area. . This absolute distance is measured by laser triangulation.

  The expansion temperature is usually always higher than the drying temperature.

  7 and 8, the adhesive according to the present invention is shown in cross section from the side. FIG. 7 shows a cross section from the side of the sample based on Example 5, and FIG. 8 shows a cross section from the side of the sample based on Example 8.

  Adhesive foaming using microballoons improves adhesion and application characteristics.

  This reduction in adhesion loss is facilitated by the high surface quality that results from pushing the expanded microballoons back into the polymer matrix during the coating process.

  In addition, foamed self-adhesives can be compared to unfoamed adhesives based on the same polymer, for example, improved impact resistance at low temperatures, increased adhesion to rough substrates, relatively large cushioning properties and / or Additional performance characteristics have been gained, such as sealing properties or adhesion of foam adhesive to uneven substrates, relatively favorable crush / curing behavior, and improved compression capability.

  A more detailed description of the characteristic properties or additional functions of the pressure-sensitive adhesive according to the invention will be given in part in the examples.

  In the following, the present invention is described in more detail by means of several examples.

  In this case, the pressure sensitive adhesive components were dissolved in benzine / toluene / acetone at 40%, mixed with microballoons suspended in benzine, and applied to the PET film with release silicone by the application bar. Was applied at the desired layer thickness, followed by evaporation of the solvent at 100 ° C. for 15 minutes, thus drying the adhesive layer.

  After drying, the adhesive layer was covered with a second layer, a PET liner, without any aeration and foamed in an oven at 150 ° C. for 5 minutes between both liners. Foaming between the two liners makes it possible to obtain products with a particularly smooth surface. The RA values of all the examples given are less than 15 μm.

A pressure-sensitive adhesive strip having a desired size was obtained by die cutting.
Examples 1 to 3

  Among these, Irganox 1010 (phenolic antioxidant) is used as an antiaging agent.

  According to Examples 1 to 3, how the increase in the content of the microballoon in the adhesive affects, more specifically, how it affects the adhesive compared to an unfoamed adhesive of the same thickness. Indicated.

Results • Impact loading in the z-plane increases as the microballoon content increases (falling ball).
The impact load in the x and y planes increases as the microballoon content increases, and the maximum value can be observed when the microballoon content is 1.5% by weight (lateral impact toughness).
• The peel force decreases as the microballoon content increases, even though impact load resistance increases.
Examples 4-7

  Examples 4 to 7 show how the increase in the content of the microballoon in the adhesive affects, in particular how it affects the unfoamed adhesive.

Results • A clear improvement in impact resistance can already be measured with a microballoon content of 0.5% by weight (falling ball).
-Impact load resistance increases as the microballoon content increases.
• The strip force decreases as the microballoon content increases.
Examples 8-9

  Examples 8 and 9 compare three layers of samples with each other.

Comparative Example 2 consists of a 50 μm PU film as an intermediate support, on both sides of the PU film, the unfoamed adhesive based on the presented composition has an adhesive application amount of 25 g / m ² and a layer thickness of 25 μm, It is given on both sides.

Example 8 consists of a 50 μm PU film as an intermediate support, on both sides of the intermediate support, an unfoamed adhesive based on the presented composition has an adhesive application thickness of 20 g / m ² and a layer thickness, respectively. It is 20 μm and is applied on both sides. Both sides of this sample were covered with a PET liner and foamed in an oven at 150 ° C. for 5 minutes to a total thickness of 100 μm.

Example 9 consists of a 30 μm PU film as an intermediate support, on both sides of the intermediate support, an unfoamed adhesive based on the composition presented has a thickness and layer thickness of 28 g / m ² respectively. It is 28 μm and is applied on both sides. Both sides of this sample were covered with a PET liner and foamed in an oven at 150 ° C. for 5 minutes to a total thickness of 100 μm.

  Examples 8 and 9 show how the foamed adhesive has an effect on the peel angle of the adhesive strip.

Results • The foamed three-layer structure still exhibits high impact load resistance and no tear at 180 ° and 90 ° peel angles.
The foamed three-layer structure is more resistant to tearing than the unfoamed three-layer structure of the same thickness at a 90 ° peel angle.

Test Methods All measurements were performed at 23 ° C. and 50% relative humidity unless otherwise indicated.

  Mechanical and adhesion technical data were determined as follows.

Restoring force or elasticity To measure the restoring force, the pressure sensitive adhesive strip was stretched 100%, held at this elongation for 30 seconds, and then loosened. After a waiting time of 1 minute, the length was measured again.

Thereafter, the restoring force is calculated as follows.
RV = ((L ₁₀₀ -L _end ) / L ₀ ) × 100
RV = restoring force in% L ₁₀₀ : length of the adhesive strip after stretching 100% L ₀ : length of the strip of adhesive before stretching L _end : length of the strip of adhesive after relaxation for 1 minute

  In this case, the restoring force corresponds to the elasticity.

Tear Elongation, Tensile Strength, and Stress at 50% Elongation Tension elongation, tensile strength, and stress at 50% elongation are based on DIN 53504, using dumbbell size S3 specimens per minute Measurements were taken at a separation speed of 300 mm. The test atmosphere was 23 ° C. and 50% relative humidity.

Peeling force Peeling force (strip force or strip stress) was determined using an adhesive material film measuring 50 mm long and 20 mm wide with a knob region at the top that was not pressure sensitive. The adhesive material film was affixed between two steel plates that were arranged exactly equally to each other with dimensions of 50 mm × 30 mm, each with a pressing force of 50 Newtons. At the lower end of this steel plate, there is one hole for hooking an S-shaped steel hook. The lower end of the steel hook is fitted with a further steel plate, which allows the test configuration to be fixed for measurement on the lower clamp of the tensile tester. The patch is stored at + 40 ° C. for a period of 24 hours. After reconditioning to room temperature, the strips of adhesive film are peeled off at a pulling rate of 1000 mm per minute, parallel to the application surface and without touching the edge area of both steel plates. At that time, the necessary peeling force is measured by Newton (N). Adhesive strip from the steel base, presents a mean value of the strip stress values measured within a range that is peeled off between the patch length 10mm~40mm (mm ² per N).

Tear test A 10 mm wide and 40 mm long strip is die cut from the adhesive tape to be tested. These strips are 30 mm long and are glued to a PC plate conditioned with ethanol, thus protruding a 10 mm long knob. The second PC plate is bonded to the second surface of the pasted strip, and more specifically, the two PC plates are bonded so as to overlap each other. On this composite, the 4 kg roller is rotated 10 times (5 reciprocations). After a 24-hour curing period, use the knob to pull the strips by hand a) at an angle of 90 ° and b) at an angle of 180 °,
Strip from adhesive joint.

  Evaluate how many samples can be removed again without residue.

Adhesive Resin Softening Temperature Adhesive resin softening temperature is carried out according to a corresponding method known as the ring and ball method and standardized according to ASTM E28.

DACP
DACP is the diacetone cloud point and is determined by cooling a heated solution of 5 g of resin, 5 g of xylene, and 5 g of diacetone alcohol to the point where the solution becomes cloudy.

Ball drop test (impact toughness, falling ball)
A square and frame-shaped sample was cut from the adhesive tape to be tested (outside dimension 33 mm × 33 mm; crosspiece width 3.0 mm; inner dimension (window cutout portion) 27 mm × 27 mm). This sample was adhered onto an ABS frame (outer dimensions 50 mm × 50 mm; crosspiece width 12.5 mm; inner dimensions (window cutout portion) 25 mm × 25 mm; thickness 3 mm). A PMMA window of 35 mm × 35 mm was bonded to the other surface of the double-sided adhesive tape. The ABS frame, the adhesive tape frame, and the PMMA window were attached so that the geometric center and the diagonal line overlap each other (the corner above the corner). The sticking area was 360 mm ² . The patch was pressed at 10 bar for 5 seconds and then stored for 24 hours at 23 ° C./50% relative humidity.

  Immediately after storage, the adhesive composite consisting of the ABS frame, adhesive tape, and PMMA board is faced down with the composite aligned horizontally and with the PMMA board hanging without support. Then, the ABS frame was placed on the frame base (sample holder) with the protruding edge. The steel balls having the respective weights were dropped on the samples arranged in this way vertically from the height of 250 cm (through the ABS frame window) at the center of the PMMA plate (measurement condition 23 ° C., relative humidity 50%). ). For each sample, three tests were performed if the PMMA plate was not removed earlier.

  The ball drop test is considered acceptable if the sticking does not come off in any of the three tests.

The energy was calculated as follows so that tests with different sphere weights could be compared.
E = height [m] × sphere weight [kg] × 9.81 kg / m · s ²

Push-out strength (z plane)
The push-out test can provide data on how highly resistant the application of parts in the frame-shaped object, such as a window in the housing, is.

A rectangular frame-shaped sample was cut from the adhesive tape to be tested (outside dimension 43 mm × 33 mm; crosspiece width 2.0 mm, inner dimension (window cutout portion) 39 mm × 29 mm, and the upper and lower adhesive areas were each 288 mm ² ). This sample was made into a rectangular ABS plastic frame (ABS = acrylonitrile butadiene styrene copolymer) (outer dimensions 50 mm x 40 mm, each of the longer bars was 8 mm; each of the shorter bars was 10 mm; Window cutout portion) 30 mm × 24 mm; thickness 3 mm). A rectangular PMMA plate (PMMA = polymethyl methacrylate) having a size of 45 mm × 35 mm was adhered to the other surface of the double-sided adhesive tape sample. All of the provided adhesive areas of the adhesive tape were utilized. The ABS frame, the adhesive tape sample, and the PMMA window are attached to the geometric center, the rectangular bisector of the acute diagonal crossing angle, and the bisector of the obtuse diagonal crossing angle. Were made to overlap each other (a corner above the corner, a long side at the long side, and a short side at the short side). The sticking area was 360 mm ² . The patch was pressed at 10 bar for 5 seconds and then stored for 24 hours at 23 ° C./50% relative humidity.

  Immediately after storage, the adhesive composite consisting of the ABS frame, adhesive tape, and PMMA board is faced down with the composite aligned horizontally and with the PMMA board hanging without support. Then, the ABS frame was placed on the frame base (sample holder) with the protruding edge.

Thereafter, the indenter is moved vertically from above at a constant speed of 10 mm / s through the window of the ABS frame so that the indenter pushes the center of the PMMA plate and (the respective pressure and contact between the indenter and the plate) The momentary force (determined from the area) is recorded in relation to the time from the first contact between the indenter and the PMMA plate to just after the force drop (measuring condition 23 ° C., relative humidity 50%). The force acting immediately before the adhesive bond between the PMMA plate and the ABS frame fails (maximum force F _max in the force / time graph: unit N) is recorded as the answer to the pushout test.

Lateral impact toughness: x, y plane From the adhesive tape to be tested, a square and frame-shaped sample was cut (outside dimension 33 mm × 33 mm; crosspiece width 3.0 mm; inner dimension (window cutout portion) 27 mm × 27 mm). This sample was bonded onto an ABS frame (outer dimensions 45 mm × 45 mm; crosspiece width 10 mm; inner dimensions (window cutout portion) 25 mm × 25 mm; thickness 3 mm). A PMMA window of 35 mm × 35 mm was bonded to the other surface of the double-sided adhesive tape. The ABS frame, the adhesive tape frame, and the PMMA window were attached so that the geometric center and the diagonal line overlap each other (the corner above the corner). The sticking area was 360 mm ² . The patch was pressed at 10 bar for 5 seconds and then stored for 24 hours at 23 ° C./50% relative humidity.

  Immediately after storage, the adhesive composite consisting of the ABS frame, adhesive tape, and PMMA plate is snapped into the sample fixture at the protruding edge of the ABS frame so that the composite is vertically aligned. Tightened and fixed. Subsequently, the sample fixture was set at the center of the accommodating portion provided in the “DuPont Impact Tester”. The impact head having a weight of 300 g was set so that a rectangular impact shape having a size of 20 mm × 3 mm hits the center of the front facing the PMMA window.

  A weight of 150 g weight guided by two guide bars was dropped from a height of 3 cm perpendicularly to the composite composed of the sample fixture, the sample and the striking head (measurement conditions 23 ° C., Relative humidity 50%). The height of the falling weight was raised in 3 cm steps until the impact energy provided destroyed the sample due to lateral impact loading and the PMMA window was disengaged from the ABS frame.

The energy was calculated as follows so that tests with different samples could be compared.
E [J] = height [m] × weight mass [kg] × 9.81 kg / m · s ²

  Five samples were tested for each product and the energy average value was presented as the eigenvalue for lateral impact toughness.

Adhesive strength Determination of adhesive strength (based on AFERA 5001) is carried out as follows. A 2 mm-thick steel plate (purchased from Rocoll GmbH) or polyethylene block galvanized by galvanic treatment is used as the prescribed adherend base. The stickable surface element to be tested is cut into a width of 20 mm and a length of about 25 cm, and a handling part is provided. Immediately thereafter, a 4 kg steel roller is fed at a speed of 10 m / min to each selected adherend. Press 5 times. Immediately thereafter, using a tensile tester (Zwick), the stickable surface element is peeled off from the adherend substrate at a speed of v = 300 mm / min at an angle of 180 °, and the force required for this is measured at room temperature. . The measured value (N / cm) is provided as an average value from three individual measurements.

Static glass transition temperature Tg
The glass transition point (synonymously referred to as the glass transition temperature) is based on DIN 53 765; especially chapters 7.1 and 8.1, but with a uniform 10 K / min in all heating and cooling steps. Presented as a result of measurements by differential scanning calorimetry DDK (DSC) at heating and cooling rates (DIN 53 765; Chapter 7.1; see note 1). The prescribed amount of sample is 20 mg.

Claims (22)

A pressure-sensitive adhesive strip comprising one or more adhesive layers, which can be re-peeled substantially free of residue and breakage by stretching and stretching on the application surface, all of the adhesive layers being microballoons Comprising a pressure sensitive adhesive foamed by, optionally including one or more intermediate support layers,
The pressure-sensitive adhesive strip is mainly composed of the adhesive layer, optionally having one or more intermediate support layers, and the pressure-sensitive adhesive strip has one outer upper surface and one outer lower surface. A pressure sensitive adhesive strip characterized in that it is formed from one or more of said adhesive layers.   The pressure-sensitive adhesive strip according to claim 1, wherein the pressure-sensitive adhesive strip comprises a single adhesive layer.   3. Pressure-sensitive adhesive strip according to claim 1 or 2, wherein the pressure-sensitive adhesive strip consists of the adhesive layer with a single intermediate support layer, in particular consisting of a polymer film.   The pressure sensitive adhesive is based on a vinyl aromatic block copolymer and an adhesive resin, which is at least 75% by weight (based on the total resin proportion) and has a DACP (diacetone alcohol cloud point) of −20. 4. The resin according to claim 1, wherein a resin having a softening temperature (ring-and-ball type) of 70 ° C. or higher, preferably 100 ° C. or higher is selected. The pressure-sensitive adhesive strip.   As pressure sensitive adhesives, polymer blocks formed mainly by vinyl aromatics, preferably styrene (A blocks) and polymer blocks formed mainly by polymerization of 1,3-dienes such as butadiene and isoprene (B blocks) or both 5. Pressure-sensitive adhesive strip according to any one of claims 1 to 4, characterized in that a pressure-sensitive adhesive based on a block copolymer containing a copolymer of the following polymer blocks is used. As a vinyl aromatic block copolymer, a block copolymer having a structure of AB, ABAA, (AB) _n , (AB) _n X, or (ABA) _n X At least one synthetic rubber in the form
Block A represents, independently of each other, a polymer formed by the polymerization of at least one vinyl aromatic;
Block B represents, independently of one another, a polymer formed by the polymerization of conjugated dienes and / or isobutylene having 4 to 18 C atoms or a partially or fully hydrogenated derivative of such a polymer. And
-X represents the residue of a coupling reagent or initiator, and-n represents an integer ≥ 2,
The pressure-sensitive adhesive strip according to any one of claims 1-5. The vinyl aromatic for forming the block A is characterized in that it comprises styrene, α-methylstyrene, and / or other styrene derivatives, particularly preferably polystyrene,
The pressure-sensitive adhesive strip according to any one of claims 1-6. The monomer for block B is selected from the group consisting of butadiene, isoprene, ethylbutadiene, phenylbutadiene, piperylene, pentadiene, hexadiene, ethylhexadiene, and dimethylbutadiene, and any mixtures of these monomers ,
The pressure-sensitive adhesive strip according to any one of claims 1-7. The proportion of vinyl aromatic block copolymer, in particular styrene block copolymer, relative to the total pressure sensitive adhesive is at least 20% by weight, preferably at least 30% by weight, more preferably at least 35% by weight, at the same time up to 75% by weight. %, Preferably at most 65% by weight, particularly preferably at most 55% by weight,
The pressure-sensitive adhesive strip according to any one of claims 1-8. The pressure-sensitive adhesive contains an adhesive resin in an amount of 20 to 60% by weight based on the total weight of the pressure-sensitive adhesive, and preferably 30 to 50% by weight based on the total weight of the pressure-sensitive adhesive. And
The pressure-sensitive adhesive strip according to any one of claims 1-9. The adhesive resin is at least 75% by weight and is a hydrocarbon resin or a terpene resin or a mixture thereof,
The pressure-sensitive adhesive strip according to any one of claims 1-10. The adhesive has the following composition:
・ Vinyl aromatic block copolymer 20-75 wt%
・ Adhesive resin 24.6-60% by weight
・ Microballoon 0.2 ~ 10wt%
・ Additive 0.2-10% by weight
Characterized in that it consists of
A pressure-sensitive adhesive strip according to any one of the preceding claims. The adhesive has the following composition:
・ Vinyl aromatic block copolymer 35-65 wt%
・ Adhesive resin 34.6-45 wt%
・ Microballoon 0.2 ~ 10wt%
・ Additive 0.2-10% by weight
Characterized in that it consists of
The pressure-sensitive adhesive strip according to any one of claims 1-12. The adhesive has the following composition:
・ Vinyl aromatic block copolymer 30-75 wt%
・ Adhesive resin 24.8-60% by weight
・ Microballoon 0.2 ~ 10wt%
Consisting of,
The pressure-sensitive adhesive strip according to any one of claims 1-13. Adhesive microballoons, each greater than 0% to 10%, in particular between 0.25% and 5%, in particular 0.5 to 1.5% by weight relative to the total composition of the adhesive It is characterized by containing between,
The pressure-sensitive adhesive strip according to any one of claims 1-14. The absolute density of the foamed pressure sensitive adhesive is 350-990 kg / m ³ , preferably 450-970 kg / m ³ , especially 500-900 kg / m ³ and / or the relative density is 0.35-0. 99, preferably 0.45 to 0.97, especially 0.50 to 0.90,
The pressure-sensitive adhesive strip according to any one of claims 1-15. When the pressure-sensitive adhesive has an intermediate support, the foamed pressure-sensitive adhesive has an absolute density of 220 to 990 kg / m ³ , preferably 300 to 900 kg / m ³ , especially 500 to 850 kg / m ³ . And / or a relative density between 0.20 and 0.99, preferably between 0.30 and 0.90, in particular between 0.50 and 0.85. ,
The pressure-sensitive adhesive strip according to any one of claims 1 to 16. The pressure-sensitive adhesive strip is implemented in a single layer, in which case the thickness of the pressure-sensitive adhesive strip is preferably 20 μm to 2000 μm, more preferably 30 to 1000 μm, particularly preferably 50 to 600 μm or 100 μm or 150 μm or It is 300 μm,
18. A pressure sensitive adhesive strip according to any one of the preceding claims. The thickness of the intermediate support is between 20 and 60 μm, preferably 50 μm, and preferably the thickness of the same adhesive layer on the support is between 20 and 60 μm, respectively, preferably 50 μm. And
A pressure sensitive adhesive strip according to any one of the preceding claims. The pressure-sensitive adhesive strip according to any one of claims 1 to 19, wherein the thickness of the intermediate support layer is 10 to 200 µm, preferably 20 to 100 µm. The intermediate support has a tear elongation of at least 100%, preferably 300% and in some cases more than 50% restoring force,
The pressure-sensitive adhesive strip according to any one of claims 1 to 20.   Use of the pressure-sensitive adhesive strip according to any one of claims 1 to 21 for affixing components, in particular storage batteries, and electronic devices, in particular mobile phones.

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